.TH mmap_readat 3
.SH NAME
mmap_readat \- memory map a file for reading
.SH SYNTAX
.B #include <libowfat/mmap.h>

const char* \fBmmap_readat\fP(const char* \fIfilename\fR,size_t* \fIfilesize\fR,int \fIdirfd\fR);
.SH DESCRIPTION
mmap_readat opens \fIfilename\fR for reading, maps the whole file into
memory, closes the file, writes the length of the file to \fIfilesize\fR
and returns a pointer to the mapped file.

If \fIfilename\fR is a relative path and \fIdirfd\fR is not AT_FDCWD
(defined in fcntl.h),
\fIfilename\fR is interpreted relative to \fIdirfd\fR, which must be an
open directory.

The file is unmapped by the operating system if the process terminates.
It can also be manually unmapped by calling \fBmunmap\fR from
<sys/mman.h>.

If the file could not be opened or mapped, (void*)0 is returned.
.SH "SEE ALSO"
mmap_unmap(3), mmap_private(3), mmap_read(3), mmap_shared(3)
